Step 1: Go To 'Main'

Open up your Script Editor which is found in the top-right corner of the rmvx window, the icon should be a paper and a pencil right next to the Resource Manager. Scroll down until you find "Main" which is on the very bottom of the Script Editor, click on it and you will find this:

#==============================================================================
# ** Main
#------------------------------------------------------------------------------
# After defining each class, actual processing begins here.
#==============================================================================

begin
 Graphics.freeze
 $scene = Scene_Title.new
 $scene.main while $scene != nil
 Graphics.transition(30)
rescue Errno::ENOENT
 filename = $!.message.sub("No such file or directory - ", "")
 print("Unable to find file #{filename}.")
end

Step 2: Put the Script In

Find this part in the script:

#------------------------------------------------------------------------------
# After defining each class, actual processing begins here.
#==============================================================================

begin
 Graphics.freeze

And put in this command in between these two lines.

begin
 Graphics.freeze

Insert this:

Font.default_name = [""]

Fill in the

[""]

with the name of the font (You need to have the font uploaded on your computer in the "Font" folder inside your Control Panel!).

For example:

Font.default_name = ["Tahoma"]

Step 3: Saving It and Opening your Game

Finally, you should have this as your Main:

#==============================================================================
# ** Main
#------------------------------------------------------------------------------
# After defining each class, actual processing begins here.
#==============================================================================

begin
 Font.default_name = ["FONT NAME"]
 Graphics.freeze
 $scene = Scene_Title.new
 $scene.main while $scene != nil
 Graphics.transition(30)
rescue Errno::ENOENT
 filename = $!.message.sub("No such file or directory - ", "")
 print("Unable to find file #{filename}.")
end

Click "OK" and open up your game, you should have the font on your project

And if you want any extra codes to edit the font a bit, you can use these.
(Set to either True or False for the first 2)

Font.default_bold = false
Font.default_italic = true
Font.default_size =